^ See Population of the Byzantine Empire for more detailed figures taken provided by McEvedy and Jones, "Atlas of World Population History", 1978, as well as Angeliki E. Laiou, "The Economic History of Byzantium", 2002.

The Byzantine Empire was the predominantly Greek-speaking continuation of the eastern half of the Roman Empire during Late Antiquity and the Middle Ages. Its capital city was Constantinople (modern-day Istanbul), originally founded as Byzantium. Often called the Eastern Roman Empire in this context, it survived the 5th century fragmentation and fall of the Western Roman Empire and continued to exist for an additional thousand years until it fell to the Ottoman Turks in 1453. During most of its existence, the empire was the most powerful economic, cultural, and military force in Europe. Both "Byzantine Empire" and "Eastern Roman Empire" are historiographical terms created after the end of the realm; its citizens continued to refer to their empire as the Roman Empire (Ancient Greek: Βασιλεία Ῥωμαίων, tr. Basileia Rhōmaiōn; Latin: Imperium Romanum), or Romania (Ῥωμανία), and to themselves as "Romans".

Several events from the 4th to 6th centuries mark the transitional period during which the Roman Empire''s east and west divided. In 285, the emperor Diocletian (r. 284–305) partitioned the Roman Empire''s administration into eastern and western halves. Between 324 and 330, Constantine I (r. 306–337) transferred the main capital from Rome to Byzantium, later known as Constantinople ("City of Constantine") and Nova Roma ("New Rome"). Under Theodosius I (r. 379–395), Christianity became the Empire''s official state religion and others such as Roman polytheism were proscribed. And finally, under the reign of Heraclius (r. 610–641), the Empire''s military and administration were restructured and adopted Greek for official use instead of Latin. Thus, although it continued the Roman state and maintained Roman state traditions, modern historians distinguish Byzantium from ancient Rome insofar as it was oriented towards Greek rather than Latin culture, and characterised by Orthodox Christianity rather than Roman polytheism.

The borders of the Empire evolved significantly over its existence, as it went through several cycles of decline and recovery. During the reign of Justinian I (r. 527–565), the Empire reached its greatest extent after reconquering much of the historically Roman western Mediterranean coast, including north Africa, Italy, and Rome itself, which it held for two more centuries. During the reign of Maurice (r. 582–602), the Empire''s eastern frontier was expanded and the north stabilised. However, his assassination caused a two-decade-long war with SassanidPersia which exhausted the Empire''s resources and contributed to major territorial losses during the Muslim conquests of the 7th century. In a matter of years the Empire lost its richest provinces, Egypt and Syria, to the Arabs.

During the Macedonian dynasty (10th–11th centuries), the Empire again expanded and experienced a two-century long renaissance, which came to an end with the loss of much of Asia Minor to the SeljukTurks after the Battle of Manzikert in 1071. This battle opened the way for the Turks to settle in Anatolia as a homeland.

The final centuries of the Empire exhibited a general trend of decline. It struggled to recover during the 12th century, but was delivered a mortal blow during the Fourth Crusade, when Constantinople was sacked and the Empire dissolved and divided into competing Byzantine Greek and Latin realms. Despite the eventual recovery of Constantinople and re-establishment of the Empire in 1261, Byzantium remained only one of several small rival states in the area for the final two centuries of its existence. Its remaining territories were progressively annexed by the Ottomans over the 15th century. The Fall of Constantinople to the Ottoman Empire in 1453 finally ended the Empire.

The first use of the term "Byzantine" to label the later years of the Roman Empire was in 1557, when the German historian Hieronymus Wolf published his work Corpus Historiæ Byzantinæ, a collection of historical sources. The term comes from "Byzantium", the name of the city of Constantinople before it became Constantine''s capital. This older name of the city would rarely be used from this point onward except in historical or poetic contexts. The publication in 1648 of the Byzantine du Louvre (Corpus Scriptorum Historiae Byzantinae), and in 1680 of Du Cange''s Historia Byzantina further popularised the use of "Byzantine" among French authors, such as Montesquieu. However, it was not until the mid-19th century that the term came into general use in the Western world. As regards the English historiography in particular, the first occasion of the "Byzantine Empire" appears in an 1857 work of George Finlay (History of the Byzantine Empire from 716 to 1057).

The Byzantine Empire was known to its inhabitants as the "Roman Empire", the "Empire of the Romans" (Latin: Imperium Romanum, Imperium Romanorum; Greek: Βασιλεία τῶν Ῥωμαίων Basileia tōn Rhōmaiōn, Ἀρχὴ τῶν Ῥωμαίων Archē tōn Rhōmaiōn), "Romania" (Latin: Romania; Greek: Ῥωμανία Rhōmania), the "Roman Republic" (Latin: Res Publica Romana; Greek: Πολιτεία τῶν Ῥωμαίων Politeia tōn Rhōmaiōn), Graikia (Greek: Γραικία), and also as Rhōmais (Greek: Ῥωμαΐς). The inhabitants called themselves Romaioi and Graikoi, and even as late as the 19th century Greeks typically referred to their modern language as Romaika and Graikika.

Although the Byzantine Empire had a multi-ethnic character during most of its history and preserved Romano-Hellenistic traditions, it became identified by its western and northern contemporaries with its increasingly predominant Greek element. The occasional use of the term "Empire of the Greeks" (Latin: Imperium Graecorum) in the West to refer to the Eastern Roman Empire and of the Byzantine Emperor as Imperator Graecorum (Emperor of the Greeks) were also used to separate it from the prestige of the Roman Empire within the new kingdoms of the West.

The authority of the Byzantine emperor as the legitimate Roman emperor was challenged by the coronation of Charlemagne as Imperator Augustus by Pope Leo III in the year 800. Needing Charlemagne''s support in his struggle against his enemies in Rome, Leo used the lack of a male occupant of the throne of the Roman Empire at the time to claim that it was vacant and that he could therefore crown a new Emperor himself. Whenever the Popes or the rulers of the West made use of the name Roman to refer to the Eastern Roman Emperors, they usually preferred the term Imperator Romaniae (meaning Emperor of Romania) instead of Imperator Romanorum (meaning Emperor of the Romans), a title that they applied only to Charlemagne and his successors.

No such distinction existed in the Islamic and Slavic worlds, where the Empire was more straightforwardly seen as the continuation of the Roman Empire. In the Islamic world, the Roman Empire was known primarily as Rûm. The name millet-i Rûm, or “Roman nation,” was used by the Ottomans through the 20th century to refer to the former subjects of the Byzantine Empire, that is, the Orthodox Christian community within Ottoman realms.

History For more details on this topic, see History of the Byzantine Empire. Early historyThe Baptism of Constantine painted by Raphael''s pupils (1520–1524, fresco, Vatican City, Apostolic Palace); Eusebius of Caesarea records that (as was common among converts of early Christianity) Constantine delayed receiving baptism until shortly before his death

The Roman army succeeded in conquering many territories covering the entire Mediterranean region and coastal regions in southwestern Europe and north Africa. These territories were home to many different cultural groups, both urban populations and rural populations. Generally speaking, the eastern Mediterranean provinces were more urbanised than the western, having previously been united under the Macedonian Empire and Hellenised by the influence of Greek culture.

The West also suffered more heavily from the instability of the 3rd century AD. This distinction between the established Hellenised East and the younger Latinised West persisted and became increasingly important in later centuries, leading to a gradual estrangement of the two worlds.

Divisions of the Roman Empire See also: Byzantium under the Constantinian and Valentinian dynasties

To maintain control and improve administration, various schemes to divide the work of the Roman Emperor by sharing it between individuals were tried between 285 and 324, from 337 to 350, from 364 to 392, and again between 395 and 480. Although the administrative subdivisions varied, they generally involved a division of labour between East and West. Each division was a form of power-sharing (or even job-sharing), for the ultimate imperium was not divisible and therefore the empire remained legally one state—although the co-emperors often saw each other as rivals or enemies.

In 293, emperor Diocletian created a new administrative system (the tetrarchy), to guarantee security in all endangered regions of his Empire. He associated himself with a co-emperor (Augustus), and each co-emperor then adopted a young colleague given the title of Caesar, to share in their rule and eventually to succeed the senior partner. The tetrarchy collapsed, however, in 313 and a few years later Constantine I reunited the two administrative divisions of the Empire as sole Augustus.

Recentralisation

In 330, Constantine moved the seat of the Empire to Constantinople, which he founded as a second Rome on the site of Byzantium, a city strategically located on the trade routes between Europe and Asia and between the Mediterranean and the Black Sea. Constantine introduced important changes into the Empire''s military, monetary, civil and religious institutions. As regards his economic policies in particular, he has been accused by certain scholars of "reckless fiscality", but the gold solidus he introduced became a stable currency that transformed the economy and promoted development.

Under Constantine, Christianity did not become the exclusive religion of the state, but enjoyed imperial preference, because the emperor supported it with generous privileges. Constantine established the principle that emperors could not settle questions of doctrine on their own, but should summon instead general ecclesiastical councils for that purpose. His convening of both the Synod of Arles and the First Council of Nicaea indicated his interest in the unity of the Church, and showcased his claim to be its head.

The Roman Empire during the reigns of Leo I (east) and Majorian (west) in 460 AD. Roman rule in the west would last less than two more decades, whereas the territory of the east would remain static until the reconquests of Justinian I.

In 395, Theodosius I bequeathed the imperial office jointly to his sons: Arcadius in the East and Honorius in the West, once again dividing Imperial administration. In the 5th century the Eastern part of the empire was largely spared the difficulties faced by the West—due in part to a more established urban culture and greater financial resources, which allowed it to placate invaders with tribute and pay foreign mercenaries. This success allowed Theodosius II to focus on the codification of the Roman law and the further fortification of the walls of Constantinople, which left the city impervious to most attacks until 1204.

To fend off the Huns, Theodosius had to pay an enormous annual tribute to Attila. His successor, Marcian, refused to continue to pay the tribute, but Attila had already diverted his attention to the West. After his death in 453, the Hunnic Empire collapsed, and many of the remaining Huns were often hired as mercenaries by Constantinople.

Loss of the western Roman Empire

After the fall of Attila, the Eastern Empire enjoyed a period of peace, while the Western Empire deteriorated due to continuing migration and expansion by the Germanic nations (its end is usually dated in 476 when the Germanic Roman general Odoacer deposed the titular Western Emperor Romulus Augustulus). In 480 Emperor Zeno abolished the division of the Empire, making himself sole Emperor. Odoacer, now ruler of Italy, was nominally Zeno''s subordinate but acted with complete autonomy, eventually providing support to a rebellion against the Emperor.

Zeno negotiated with the invading Ostrogoths, who had settled in Moesia, convincing the Gothic king Theodoric to depart for Italy as magister militum per Italiam ("commander in chief for Italy") with the aim of deposing Odoacer. By urging Theodoric to conquer Italy, Zeno rid the Eastern Empire of an unruly subordinate (Odoacer) and moved another (Theodoric) further from the heart of the Empire. After Odoacer''s defeat in 493, Theodoric ruled Italy on his own, although he was never recognised by the eastern emperors as "king" (rex).

In 491, Anastasius I, an aged civil officer of Roman origin, became Emperor, but it was not until 497 that the forces of the new emperor effectively took the measure of Isaurian resistance. Anastasius revealed himself as an energetic reformer and an able administrator. He perfected Constantine I''s coinage system by definitively setting the weight of the copper follis, the coin used in most everyday transactions. He also reformed the tax system and permanently abolished the chrysargyron tax. The State Treasury contained the enormous sum of 320,000 lb (150,000 kg) of gold when Anastasius died in 518.

Reconquest of the western provinces See also: Byzantine Empire under the Justinian dynastyJustinian I depicted on one of the famous mosaics of the Basilica of San Vitale, Ravenna.

Justinian I, the son of an Illyrian peasant, may already have exerted effective control during the reign of his uncle, Justin I (518–527). He assumed the throne in 527, and oversaw a period of recovery of former territories. In 532, attempting to secure his eastern frontier, he signed a peace treaty with Khosrau I of Persia agreeing to pay a large annual tribute to the Sassanids. In the same year, he survived a revolt in Constantinople (the Nika riots), which solidified his power but ended with the deaths of a reported 30,000 to 35,000 rioters on his orders.

In 529, a ten-man commission chaired by John the Cappadocian revised the Roman law and created a new codification of laws and jurists'' extracts. In 534, the Code was updated and, along with the enactements promulgated by Justinian after 534, it formed the system of law used for most of the rest of the Byzantine era.

The western conquests began in 533, as Justinian sent his general Belisarius to reclaim the former province of Africa from the Vandals who had been in control since 429 with their capital at Carthage. Their success came with surprising ease, but it was not until 548 that the major local tribes were subdued. In Ostrogothic Italy, the deaths of Theodoric, his nephew and heir Athalaric, and his daughter Amalasuntha had left her murderer, Theodahad (r. 534–536), on the throne despite his weakened authority.

In 535, a small Byzantine expedition to Sicily met with easy success, but the Goths soon stiffened their resistance, and victory did not come until 540, when Belisarius captured Ravenna, after successful sieges of Naples and Rome. In 535–536, Theodahad sent Pope Agapetus I to Constantinople to request the removal of Byzantine forces from Sicily, Dalmatia, and Italy. Although Agapetus failed in his mission to sign a peace with Justinian, he succeeded in having the Monophysite Patriarch Anthimus I of Constantinople denounced, despite empress Theodora''s support and protection.

The Ostrogoths were soon reunited under the command of King Totila and captured Rome in 546. Belisarius, who had been sent back to Italy in 544, was eventually recalled to Constantinople in 549. The arrival of the Armenian eunuch Narses in Italy (late 551) with an army of some 35,000 men marked another shift in Gothic fortunes. Totila was defeated at the Battle of Taginae and his successor, Teia, was defeated at the Battle of Mons Lactarius (October 552). Despite continuing resistance from a few Gothic garrisons and two subsequent invasions by the Franks and Alemanni, the war for the Italian peninsula was at an end. In 551, Athanagild, a noble from Visigothic Hispania, sought Justinian''s help in a rebellion against the king, and the emperor dispatched a force under Liberius, a successful military commander. The Empire held on to a small slice of the Iberian Peninsula coast until the reign of Heraclius.

The Eastern Roman Empire in 600 AD during the reign of Emperor Maurice.

In the east, the Roman–Persian Wars continued until 561 when the envoys of Justinian and Khosrau agreed on a 50-year peace. By the mid-550s, Justinian had won victories in most theatres of operation, with the notable exception of the Balkans, which were subjected to repeated incursions from the Slavs and the Gepids. Tribes of Serbs and Croats were later resettled in the northwestern Balkans, during the reign of Heraclius. Justinian called Belisarius out of retirement and defeated the new Hunnish threat. The strengthening of the Danube fleet caused the Kutrigur Huns to withdraw and they agreed to a treaty that allowed safe passage back across the Danube.

During the 6th century, traditional Greco-Roman culture was still influential in the Eastern empire. Philosophers such as John Philoponus drew on neoplatonic ideas in addition to Christian thought and empiricism. Nevertheless, Hellenistic philosophy began to be supplanted by or amalgamated into newer Christian philosophy. Polytheism was suppressed by the state. The closure of the Platonic Academy was a notable turning point. Hymns written by Romanos the Melodist marked the development of the Divine Liturgy, while architects and builders worked to complete the new Church of the Holy Wisdom, Hagia Sophia, which was designed to replace an older church destroyed during the Nika Revolt. The Hagia Sophia stands today as one of the major monuments of Byzantine architectural history. During the 6th and 7th centuries, the Empire was struck by a series of epidemics, which greatly devastated the population and contributed to a significant economic decline and a weakening of the Empire.

After Justinian died in 565, his successor, Justin II refused to pay the large tribute to the Persians. Meanwhile, the Germanic Lombards invaded Italy; by the end of the century only a third of Italy was in Byzantine hands. Justin''s successor, Tiberius II, choosing between his enemies, awarded subsidies to the Avars while taking military action against the Persians. Though Tiberius'' general, Maurice, led an effective campaign on the eastern frontier, subsidies failed to restrain the Avars. They captured the Balkan fortress of Sirmium in 582, while the Slavs began to make inroads across the Danube.

Maurice, who meanwhile succeeded Tiberius, intervened in a Persian civil war, placed the legitimate Khosrau II back on the throne and married his daughter to him. Maurice''s treaty with his new brother-in-law enlarged the territories of the Empire to the East and allowed the energetic Emperor to focus on the Balkans. By 602, a series of successful Byzantine campaigns had pushed the Avars and Slavs back across the Danube.

Shrinking borders Heraclian dynasty For more details on this topic, see Byzantine Empire under the Heraclian dynasty.The Byzantine Empire in 650 - by this year it had lost all of its southern provinces except the Exarchate of Africa.

After Maurice''s murder by Phocas, Khosrau used the pretext to reconquer the Roman province of Mesopotamia. Phocas, an unpopular ruler invariably described in Byzantine sources as a "tyrant", was the target of a number of Senate-led plots. He was eventually deposed in 610 by Heraclius, who sailed to Constantinople from Carthage with an icon affixed to the prow of his ship.

Following the accession of Heraclius, the Sassanid advance pushed deep into the Levant, occupying Damascus and Jerusalem and removing the True Cross to Ctesiphon. The counter-attack launched by Heraclius took on the character of a holy war, and an acheiropoietos image of Christ was carried as a military standard (similarly, when Constantinople was saved from an Avar siege in 626, the victory was attributed to the icons of the Virgin that were led in procession by Patriarch Sergius about the walls of the city).

The main Sassanid force was destroyed at Nineveh in 627, and in 629 Heraclius restored the True Cross to Jerusalem in a majestic ceremony. The war had exhausted both the Byzantines and Sassanids, however, and left them extremely vulnerable to the Muslim forces that emerged in the following years. The Byzantines suffered a crushing defeat by the Arabs at the Battle of Yarmouk in 636, while Ctesiphon fell in 637.

Siege of Constantinople (674–678)

The Arabs, now firmly in control of Syria and the Levant, sent frequent raiding parties deep into Asia Minor, and in 674–678 laid siege to Constantinople itself. The Arab fleet was finally repulsed through the use of Greek fire, and a thirty-years'' truce was signed between the Empire and the UmayyadCaliphate. However, the Anatolian raids continued unabated, and accelerated the demise of classical urban culture, with the inhabitants of many cities either refortifying much smaller areas within the old city walls, or relocating entirely to nearby fortresses. Constantinople itself dropped substantially in size, from 500,000 inhabitants to just 40,000–70,000, and, like other urban centres, it was partly ruralised. The city also lost the free grain shipments in 618, after Egypt fell first to the Persians and then to the Arabs, and public wheat distribution ceased.

The void left by the disappearance of the old semi-autonomous civic institutions was filled by the theme system, which entailed dividing Asia Minor into "provinces" occupied by distinct armies that assumed civil authority and answered directly to the imperial administration. This system may have had its roots in certain ad hoc measures taken by Heraclius, but over the course of the 7th century it developed into an entirely new system of imperial governance. The massive cultural and institutional restructuring of the Empire consequent on the loss of territory in the 7th century has been said to have caused a decisive break in east Mediterranean Romanness and that the Byzantine state is subsequently best understood as another successor state rather than a real continuation of the Roman Empire.

The Greek fire was first used by the Byzantine Navy during the Byzantine-Arab Wars (from the Madrid Skylitzes, Biblioteca Nacional de España, Madrid).

The withdrawal of large numbers of troops from the Balkans to combat the Persians and then the Arabs in the east opened the door for the gradual southward expansion of Slavic peoples into the peninsula, and, as in Asia Minor, many cities shrank to small fortified settlements. In the 670s, the Bulgars were pushed south of the Danube by the arrival of the Khazars. In 680, Byzantine forces sent to disperse these new settlements were defeated.

In 681, Constantine IV signed a treaty with the Bulgar khan Asparukh, and the new Bulgarian state assumed sovereignty over a number of Slavic tribes that had previously, at least in name, recognised Byzantine rule. In 687–688, the final Heraclian emperor, Justinian II, led an expedition against the Slavs and Bulgarians, and made significant gains, although the fact that he had to fight his way from Thrace to Macedonia demonstrates the degree to which Byzantine power in the north Balkans had declined.

Justinian II attempted to break the power of the urban aristocracy through severe taxation and the appointment of "outsiders" to administrative posts. He was driven from power in 695, and took shelter first with the Khazars and then with the Bulgarians. In 705, he returned to Constantinople with the armies of the Bulgarian khan Tervel, retook the throne, and instituted a reign of terror against his enemies. With his final overthrow in 711, supported once more by the urban aristocracy, the Heraclian dynasty came to an end.

Isaurian dynasty to the accession of Basil I For more details on this topic, see Byzantine Empire under the Isaurian dynasty.The Byzantine Empire at the accession of Leo III, c. 717. Striped area indicates land raided by the Arabs.

Leo III the Isaurian turned back the Muslim assault in 718 and addressed himself to the task of reorganising and consolidating the themes in Asia Minor. His successor, Constantine V, won noteworthy victories in northern Syria and thoroughly undermined Bulgarian strength.

Taking advantage of the Empire''s weakness after the Revolt of Thomas the Slav in the early 820s, the Arabs re-emerged and captured Crete. They also successfully attacked Sicily, but in 863 general Petronas gained a decisive victory against Umar al-Aqta, the emir of Melitene (Malatya). Under the leadership of emperor Krum, the Bulgarian threat also re-emerged, but in 815–816 Krum''s son, Omurtag, signed a peace treaty with Leo V.

Religious dispute over iconoclasm Main article: Byzantine iconoclasm

The 8th and early 9th centuries were also dominated by controversy and religious division over Iconoclasm, which was the main political issue in the Empire for over a century. Icons (here meaning all forms of religious imagery) were banned by Leo and Constantine from around 730, leading to revolts by iconodules (supporters of icons) throughout the empire. After the efforts of empress Irene, the Second Council of Nicaea met in 787 and affirmed that icons could be venerated but not worshiped. Irene is said to have endeavoured to negotiate a marriage between herself and Charlemagne, but, according to Theophanes the Confessor, the scheme was frustrated by Aetios, one of her favourites.

In the early 9th century, Leo V reintroduced the policy of iconoclasm, but in 843 empress Theodora restored the veneration of icons with the help of Patriarch Methodios. Iconoclasm played a part in the further alienation of East from West, which worsened during the so-called Photian schism, when Pope Nicholas I challenged the elevation of Photios to the patriarchate.

The accession of Basil I to the throne in 867 marks the beginning of the Macedonian dynasty, which would rule for the next two and a half centuries. This dynasty included some of the most able emperors in Byzantium''s history, and the period is one of revival and resurgence. The Empire moved from defending against external enemies to reconquest of territories formerly lost.

In addition to a reassertion of Byzantine military power and political authority, the period under the Macedonian dynasty is characterised by a cultural revival in spheres such as philosophy and the arts. There was a conscious effort to restore the brilliance of the period before the Slavic and subsequent Arab invasions, and the Macedonian era has been dubbed the "Golden Age" of Byzantium. Though the Empire was significantly smaller than during the reign of Justinian, it had regained significant strength, as the remaining territories were less geographically dispersed and more politically, economically, and culturally integrated.

Wars against the Arabs For more details on this topic, see Byzantine–Arab Wars (780–1180).The general Leo Phokas defeats the Hamdanid Emirate of Aleppo at Andrassos in 960, from the Madrid Skylitzes.

In the early years of Basil I''s reign, Arab raids on the coasts of Dalmatia were successfully repelled, and the region once again came under secure Byzantine control. This enabled Byzantine missionaries to penetrate to the interior and convert the Serbs and the principalities of modern-day Herzegovina and Montenegro to Orthodox Christianity. An attempt to retake Malta ended disastrously, however, when the local population sided with the Arabs and massacred the Byzantine garrison.

By contrast, the Byzantine position in Southern Italy was gradually consolidated so that by 873 Bari had once again come under Byzantine rule, and most of Southern Italy would remain in the Empire for the next 200 years. On the more important eastern front, the Empire rebuilt its defences and went on the offensive. The Paulicians were defeated and their capital of Tephrike (Divrigi) taken, while the offensive against the Abbasid Caliphate began with the recapture of Samosata.

The military successes of the 10th century were coupled with a major cultural revival, the so-called Macedonian Renaissance. Miniature from the Paris Psalter, an example of Hellenistic-influenced art.

Under Basil''s son and successor, Leo VI the Wise, the gains in the east against the now weak Abbasid Caliphate continued. However, Sicily was lost to the Arabs in 902, and in 904 Thessaloniki, the Empire''s second city, was sacked by an Arab fleet. The weakness of the Empire in the naval sphere was quickly rectified, so that a few years later a Byzantine fleet had re-occupied Cyprus, lost in the 7th century, and also stormed Laodicea in Syria. Despite this revenge, the Byzantines were still unable to strike a decisive blow against the Muslims, who inflicted a crushing defeat on the imperial forces when they attempted to regain Crete in 911.

The death of the Bulgarian tsar Simeon I in 927 severely weakened the Bulgarians, allowing the Byzantines to concentrate on the eastern front. Melitene was permanently recaptured in 934, and in 943 the famous general John Kourkouas continued the offensive in Mesopotamia with some noteworthy victories, culminating in the reconquest of Edessa. Kourkouas was especially celebrated for returning to Constantinople the venerated Mandylion, a relic purportedly imprinted with a portrait of Christ.

The soldier-emperors Nikephoros II Phokas (reigned 963–969) and John I Tzimiskes (969–976) expanded the empire well into Syria, defeating the emirs of north-west Iraq. The great city of Aleppo was taken by Nikephoros in 962, and the Arabs were decisively expelled from Crete in 963. The recapture of Crete put an end to Arab raids in the Aegean, allowing mainland Greece to flourish once again. Cyprus was permanently retaken in 965, and the successes of Nikephoros culminated in 969 with the recapture of Antioch, which he incorporated as a province of the Empire. His successor John Tzimiskes recaptured Damascus, Beirut, Acre, Sidon, Caesarea, and Tiberias, putting Byzantine armies within striking distance of Jerusalem, although the Muslim power centres in Iraq and Egypt were left untouched. After much campaigning in the north, the last Arab threat to Byzantium, the rich province of Sicily, was targeted in 1025 by Basil II, who died before the expedition could be completed. Nevertheless, by that time the Empire stretched from the straits of Messina to the Euphrates and from the Danube to Syria.

Wars against the Bulgarian Empire For more details on this topic, see Byzantine–Bulgarian wars.Emperor Basil II (r. 976–1025)

The traditional struggle with the See of Rome continued through the Macedonian period, spurred by the question of religious supremacy over the newly Christianised state of Bulgaria. Ending eighty years of peace between the two states, the powerful Bulgarian tsar Simeon I invaded in 894 but was pushed back by the Byzantines, who used their fleet to sail up the Black Sea to attack the Bulgarian rear, enlisting the support of the Hungarians. The Byzantines were defeated at the Battle of Boulgarophygon in 896, however, and agreed to pay annual subsidies to the Bulgarians.

Leo the Wise died in 912, and hostilities soon resumed as Simeon marched to Constantinople at the head of a large army. Though the walls of the city were impregnable, the Byzantine administration was in disarray and Simeon was invited into the city, where he was granted the crown of basileus (emperor) of Bulgaria and had the young emperor Constantine VII marry one of his daughters. When a revolt in Constantinople halted his dynastic project, he again invaded Thrace and conquered Adrianople. The Empire now faced the problem of a powerful Christian state within a few days'' marching distance from Constantinople, as well as having to fight on two fronts.

A great imperial expedition under Leo Phocas and Romanos I Lekapenos ended with another crushing Byzantine defeat at the Battle of Achelous in 917, and the following year the Bulgarians were free to ravage northern Greece. Adrianople was plundered again in 923, and a Bulgarian army laid siege to Constantinople in 924. Simeon died suddenly in 927, however, and Bulgarian power collapsed with him. Bulgaria and Byzantium entered a long period of peaceful relations, and the Empire was now free to concentrate on the eastern front against the Muslims. In 968, Bulgaria was overrun by the Rus'' under Sviatoslav I of Kiev, but three years later, John I Tzimiskes defeated the Rus'' and re-incorporated Eastern Bulgaria into the Byzantine Empire.

The extent of the Empire under Basil II

Bulgarian resistance revived under the rule of the Cometopuli dynasty, but the new emperor Basil II (r. 976–1025) made the submission of the Bulgarians his primary goal. Basil''s first expedition against Bulgaria, however, resulted in a humiliating defeat at the Gates of Trajan. For the next few years, the emperor would be preoccupied with internal revolts in Anatolia, while the Bulgarians expanded their realm in the Balkans. The war dragged on for nearly twenty years. The Byzantine victories of Spercheios and Skopje decisively weakened the Bulgarian army, and in annual campaigns, Basil methodically reduced the Bulgarian strongholds. At the Battle of Kleidion in 1014 the Bulgarians were annihilated: their army was captured, and it is said that 99 out of every 100 men were blinded, with the hundredth man left with one eye so he could lead his compatriots home. When Tsar Samuil saw the broken remains of his once gallant army, he died of shock. By 1018, the last Bulgarian strongholds had surrendered, and the country became part of the Empire. This victory restored the Danube frontier, which had not been held since the days of the emperor Heraclius.

Relations with the Kievan Rus''Rus'' under the walls of Constantinople (860)

Between 850 and 1100, the Empire developed a mixed relationship with the new state of the Kievan Rus'', which had emerged to the north across the Black Sea. This relationship would have long-lasting repercussions in the history of the East Slavs, and the Empire quickly became the main trading and cultural partner for Kiev. The Rus'' launched their first attack against Constantinople in 860, pillaging the suburbs of the city. In 941, they appeared on the Asian shore of the Bosphorus, but this time they were crushed, an indication of the improvements in the Byzantine military position after 907, when only diplomacy had been able to push back the invaders. Basil II could not ignore the emerging power of the Rus'', and, following the example of his predecessors, he used religion as a means for the achievement of political purposes. Rus''–Byzantine relations became closer following the marriage of the Anna Porphyrogeneta to Vladimir the Great in 988, and the subsequent Christianisation of the Rus''. Byzantine priests, architects, and artists were invited to work on numerous cathedrals and churches around Rus'', expanding Byzantine cultural influence even further, while numerous Rus'' served in the Byzantine army as mercenaries, most notably as the famous Varangian Guard.

Even after the Christianisation of the Rus'', however, relations were not always friendly. The most serious conflict between the two powers was the war of 968–971 in Bulgaria, but several Rus'' raiding expeditions against the Byzantine cities of the Black Sea coast and Constantinople itself are also recorded. Although most were repulsed, they were often followed by treaties that were generally favourable to the Rus'', such as the one concluded at the end of the war of 1043, during which the Rus'' gave an indication of their ambitions to compete with the Byzantines as an independent power.

ApexConstantinople became the largest and wealthiest city in Europe between the 9th and 11th centuries

By 1025, the date of Basil II''s death, the Byzantine Empire stretched from Armenia in the east to Calabria in Southern Italy in the west. Many successes had been achieved, ranging from the conquest of Bulgaria to the annexation of parts of Georgia and Armenia, and the reconquest of Crete, Cyprus, and the important city of Antioch. These were not temporary tactical gains but long-term reconquests.

Leo VI achieved the complete codification of Byzantine law in Greek. This monumental work of 60 volumes became the foundation of all subsequent Byzantine law and is still studied today. Leo also reformed the administration of the Empire, redrawing the borders of the administrative subdivisions (the Themata, or "Themes") and tidying up the system of ranks and privileges, as well as regulating the behaviour of the various trade guilds in Constantinople. Leo''s reform did much to reduce the previous fragmentation of the Empire, which henceforth had one center of power, Constantinople. However, the increasing military success of the Empire greatly enriched and empowered the provincial nobility with respect to the peasantry, who were essentially reduced to a state of serfdom.

Under the Macedonian emperors, the city of Constantinople flourished, becoming the largest and wealthiest city in Europe, with a population of approximately 400,000 in the 9th and 10th centuries. During this period, the Byzantine Empire employed a strong civil service staffed by competent aristocrats that oversaw the collection of taxes, domestic administration, and foreign policy. The Macedonian emperors also increased the Empire''s wealth by fostering trade with Western Europe, particularly through the sale of silk and metalwork.

The Macedonian period also included events of momentous religious significance. The conversion of the Bulgarians, Serbs and Rus'' to Orthodox Christianity permanently changed the religious map of Europe and still resonates today. Cyril and Methodius, two Byzantine Greek brothers from Thessaloniki, contributed significantly to the Christianization of the Slavs and in the process devised the Glagolitic alphabet, ancestor to the Cyrillic script.

In 1054, relations between the Eastern and Western traditions within the Christian Church reached a terminal crisis, known as the East–West Schism. Although there was a formal declaration of institutional separation, on July 16, when three papal legates entered the Hagia Sophia during Divine Liturgy on a Saturday afternoon and placed a bull of excommunication on the altar, the so-called Great Schism was actually the culmination of centuries of gradual separation.

Crisis and fragmentation

The Empire soon fell into a period of difficulties, caused to a large extent by the undermining of the theme system and the neglect of the military. Nikephoros II, John Tzimiskes, and Basil II changed the military divisions (τάγματα, tagmata) from a rapid response, primarily defensive, citizen army into a professional, campaigning army, increasingly manned by mercenaries. Mercenaries were expensive, however, and as the threat of invasion receded in the 10th century, so did the need for maintaining large garrisons and expensive fortifications. Basil II left a burgeoning treasury upon his death, but he neglected to plan for his succession. None of his immediate successors had any particular military or political talent and the administration of the Empire increasingly fell into the hands of the civil service. Efforts to revive the Byzantine economy only resulted in inflation and a debased gold coinage. The army was now seen as both an unnecessary expense and a political threat. Native troops were therefore cashiered and replaced by foreign mercenaries on specific contract.

At the same time, the Empire was faced with new enemies. Provinces in southern Italy faced the Normans, who arrived in Italy at the beginning of the 11th century. During a period of strife between Constantinople and Rome culminating in the East-West Schism of 1054, the Normans began to advance, slowly but steadily, into Byzantine Italy. Reggio, the capital of the tagma of Calabria, was captured in 1060 by Robert Guiscard, followed by Otranto in 1068. Bari, the main Byzantine stronghold in Apulia, was besieged in August 1068 and fell in April 1071. The Byzantines also lost their influence over the Dalmatian coastal cities to Peter Krešimir IV of Croatia (r. 1058–1074/1075) in 1069.

The seizure of Edessa (1031) by the Byzantines under George Maniakes and the counterattack by the Seljuk Turks

The greatest disaster took place in Asia Minor, however, where the Seljuq Turks made their first explorations across the Byzantine frontier into Armenia in 1065 and 1067. The emergency lent weight to the military aristocracy in Anatolia, who in 1068 secured the election of one of their own, Romanos Diogenes, as emperor. In the summer of 1071, Romanos undertook a massive eastern campaign to draw the Seljuks into a general engagement with the Byzantine army. At the Battle of Manzikert, Romanos suffered a surprise defeat by SultanAlp Arslan, and he was captured. Alp Arslan treated him with respect and imposed no harsh terms on the Byzantines. In Constantinople, however, a coup put in power Michael Doukas, who soon faced the opposition of Nikephoros Bryennios and Nikephoros Botaneiates. By 1081, the Seljuks had expanded their rule over virtually the entire Anatolian plateau from Armenia in the east to Bithynia in the west, and they had founded their capital at Nicaea, just 90 kilometres (56 miles) from Constantinople.

Komnenian dynasty and the crusaders See also: Byzantine Empire under the Komnenos dynasty and Komnenian restorationAlexios I, founder of the Komnenos dynasty

During the Komnenian, or Comnenian, period from about 1081 to about 1185, the five emperors of the Komnenos dynasty (Alexios I, John II, Manuel I, Alexios II, and Andronikos I) presided over a sustained, though ultimately incomplete, restoration of the military, territorial, economic, and political position of the Byzantine Empire. Although the Seljuk Turks occupied the heartland of the Empire in Anatolia, most Byzantine military efforts during this period were directed against Western powers, particularly the Normans.

The Empire under the Komnenoi played a key role in the history of the Crusades in the Holy Land, which Alexios I had helped bring about, while also exerting enormous cultural and political influence in Europe, the Near East, and the lands around the Mediterranean Sea under John and Manuel. Contact between Byzantium and the "Latin" West, including the Crusader states, increased significantly during the Komnenian period. Venetian and other Italian traders became resident in large numbers in Constantinople and the empire (there were an estimated 60,000 Latins in Constantinople alone, out of a population of three to four hundred thousand), and their presence together with the numerous Latin mercenaries who were employed by Manuel helped to spread Byzantine technology, art, literature and culture throughout the Latin West, while also leading to a flow of Western ideas and customs into the Empire.

In terms of prosperity and cultural life, the Komnenian period was one of the peaks in Byzantine history, and Constantinople remained the leading city of the Christian world in size, wealth, and culture. There was a renewed interest in classical Greek philosophy, as well as an increase in literary output in vernacular Greek. Byzantine art and literature held a pre-eminent place in Europe, and the cultural impact of Byzantine art on the west during this period was enormous and of long lasting significance.

Alexios I and the First Crusade For more details on this topic, see Alexios I Komnenos. See also: First CrusadeThe Byzantine Empire and the Sultanate of Rûm before the First Crusade

After Manzikert, a partial recovery (referred to as the Komnenian restoration) was made possible by the Komnenian dynasty. The first Komnenian emperor was Isaac I (1057–1059), after which the Doukas dynasty held power (1059–81). The Komnenoi attained power again under Alexios I in 1081. From the outset of his reign, Alexios faced a formidable attack by the Normans under Robert Guiscard and his son Bohemund of Taranto, who captured Dyrrhachium and Corfu, and laid siege to Larissa in Thessaly. Robert Guiscard''s death in 1085 temporarily eased the Norman problem. The following year, the Seljuq sultan died, and the sultanate was split by internal rivalries. By his own efforts, Alexios defeated the Pechenegs; they were caught by surprise and annihilated at the Battle of Levounion on 28 April 1091.

Having achieved stability in the West, Alexios could turn his attention to the severe economic difficulties and the disintegration of the Empire''s traditional defences. However, he still did not have enough manpower to recover the lost territories in Asia Minor and to advance against the Seljuks. At the Council of Piacenza in 1095, envoys from Alexios spoke to Pope Urban II about the suffering of the Christians of the East, and underscored that without help from the West they would continue to suffer under Muslim rule.

The brief first coinage of the Thessaloniki mint, opened by Alexios in September 1081, on his way to confront the invading Normans under Robert Guiscard

Urban saw Alexios''s request as a dual opportunity to cement Western Europe and reunite the Eastern Orthodox Church with the Roman Catholic Church under his rule. On 27 November 1095, Pope Urban II called together the Council of Clermont, and urged all those present to take up arms under the sign of the Cross and launch an armed pilgrimage to recover Jerusalem and the East from the Muslims. The response in Western Europe was overwhelming.

Alexios had anticipated help in the form of mercenary forces from the West, but he was totally unprepared for the immense and undisciplined force that soon arrived in Byzantine territory. It was no comfort to Alexios to learn that four of the eight leaders of the main body of the Crusade were Normans, among them Bohemund. Since the crusade had to pass through Constantinople, however, the Emperor had some control over it. He required its leaders to swear to restore to the empire any towns or territories they might conquer from the Turks on their way to the Holy Land. In return, he gave them guides and a military escort.

Alexios was able to recover a number of important cities and islands, and in fact much of western Asia Minor. Nevertheless, the Catholic/Latin crusaders believed their oaths were invalidated when Alexios did not help them during the siege of Antioch (he had in fact set out on the road to Antioch but had been persuaded to turn back by Stephen of Blois, who assured him that all was lost and that the expedition had already failed). Bohemund, who had set himself up as Prince of Antioch, briefly went to war with the Byzantines, but he agreed to become Alexios'' vassal under the Treaty of Devol in 1108, which marked the end of the Norman threat during Alexios'' reign.

John II, Manuel I and the Second Crusade Main articles: John II Komnenos and Manuel I KomnenosMedieval manuscript depicting the Capture of Jerusalem during the First Crusade

Alexios''s son John II Komnenos succeeded him in 1118 and ruled until 1143. John was a pious and dedicated Emperor who was determined to undo the damage to the empire suffered at the Battle of Manzikert, half a century earlier. Famed for his piety and his remarkably mild and just reign, John was an exceptional example of a moral ruler at a time when cruelty was the norm. For this reason, he has been called the Byzantine Marcus Aurelius.

During his twenty-five year reign, John made alliances with the Holy Roman Empire in the West and decisively defeated the Pechenegs at the Battle of Beroia. He thwarted Hungarian and Serbian threats during the 1120s, and in 1130 he allied himself with the German emperor Lothair III against the Norman king Roger II of Sicily.

In the later part of his reign, John focused his activities on the East, personally leading numerous campaigns against the Turks in Asia Minor. His campaigns fundamentally altered the balance of power in the East, forcing the Turks onto the defensive, while restoring to the Byzantines many towns, fortresses, and cities across the peninsula. He defeated the Danishmend emirate of Melitene and reconquered all of Cilicia, while forcing Raymond of Poitiers, Prince of Antioch, to recognise Byzantine suzerainty. In an effort to demonstrate the Emperor''s role as the leader of the Christian world, John marched into the Holy Land at the head of the combined forces of the Empire and the Crusader states; yet despite his great vigour pressing the campaign, his hopes were disappointed by the treachery of his Crusader allies. In 1142, John returned to press his claims to Antioch, but he died in the spring of 1143 following a hunting accident. Raymond was emboldened to invade Cilicia, but he was defeated and forced to go to Constantinople to beg mercy from the new Emperor.

Byzantine Empire in orange, c. 1180, at the end of the Komnenian period

John''s chosen heir was his fourth son, Manuel I Komnenos, who campaigned aggressively against his neighbours both in the west and in the east. In Palestine, Manuel allied with the Crusader Kingdom of Jerusalem and sent a large fleet to participate in a combined invasion of Fatimid Egypt. Manuel reinforced his position as overlord of the Crusader states, with his hegemony over Antioch and Jerusalem secured by agreement with Raynald, Prince of Antioch, and Amalric, King of Jerusalem. In an effort to restore Byzantine control over the ports of southern Italy, he sent an expedition to Italy in 1155, but disputes within the coalition led to the eventual failure of the campaign. Despite this military setback, Manuel''s armies successfully invaded the Southern parts of Kingdom of Hungary in 1167, defeating the Hungarians at the Battle of Sirmium. By 1168, nearly the whole of the eastern Adriatic coast lay in Manuel''s hands. Manuel made several alliances with the Pope and Western Christian kingdoms, and he successfully handled the passage of the Second Crusade through his empire.

In the east, however, Manuel suffered a major defeat in 1176 at the Battle of Myriokephalon, against the Turks. Yet the losses were quickly recovered, and in the following year Manuel''s forces inflicted a defeat upon a force of "picked Turks". The Byzantine commander John Vatatzes, who destroyed the Turkish invaders at the Battle of Hyelion and Leimocheir, not only brought troops from the capital but also was able to gather an army along the way, a sign that the Byzantine army remained strong and that the defensive program of western Asia Minor was still successful.

12th-century Renaissance For more details on this topic, see Byzantine civilisation in the twelfth century. See also: Komnenian Byzantine army''The Lamentation of Christ'' (1164), a fresco from the church of Saint Panteleimon in Nerezi near Skopje; it is considered a superb example of 12th-century Komnenian art

John and Manuel pursued active military policies, and both deployed considerable resources on sieges and on city defences; aggressive fortification policies were at the heart of their imperial military policies. Despite the defeat at Myriokephalon, the policies of Alexios, John and Manuel resulted in vast territorial gains, increased frontier stability in Asia Minor, and secured the stabilisation of the Empire''s European frontiers. From circa 1081 to circa 1180, the Komnenian army assured the Empire''s security, enabling Byzantine civilisation to flourish.

This allowed the Western provinces to achieve an economic revival that continued until the close of the century. It has been argued that Byzantium under the Komnenian rule was more prosperous than at any time since the Persian invasions of the 7th century. During the 12th century, population levels rose and extensive tracts of new agricultural land were brought into production. Archaeological evidence from both Europe and Asia Minor shows a considerable increase in the size of urban settlements, together with a notable upsurge in new towns. Trade was also flourishing; the Venetians, the Genoese and others opened up the ports of the Aegean to commerce, shipping goods from the Crusader kingdoms of Outremer and Fatimid Egypt to the west and trading with the Empire via Constantinople.

In artistic terms, there was a revival in mosaic, and regional schools of architecture began producing many distinctive styles that drew on a range of cultural influences. During the 12th century, the Byzantines provided their model of early humanism as a renaissance of interest in classical authors. In Eustathius of Thessalonica, Byzantine humanism found its most characteristic expression. In philosophy, there was resurgence of classical learning not seen since the 7th century, characterised by a significant increase in the publication of commentaries on classical works. In addition, the first transmission of classical Greek knowledge to the West occurred during the Komnenian period.

Decline and disintegration Main article: Decline of the Byzantine Empire Dynasty of the Angeloi Main article: Byzantine Empire under the Angelos dynasty

Manuel''s death on 24 September 1180 left his 11-year-old son Alexios II Komnenos on the throne. Alexios was highly incompetent at the office, but it was his mother, Maria of Antioch, and her Frankish background that made his regency unpopular. Eventually, Andronikos I Komnenos, a grandson of Alexios I, launched a revolt against his younger relative and managed to overthrow him in a violent coup d''état. Utilizing his good looks and his immense popularity with the army, he marched on to Constantinople in August 1182 and incited a massacre of the Latins. After eliminating his potential rivals, he had himself crowned as co-emperor in September 1183. He eliminated Alexios II, and took his 12-year-old wife Agnes of France for himself.

Iconium was won by the Third Crusade

Andronikos began his reign well; in particular, the measures he took to reform the government of the Empire have been praised by historians. According to George Ostrogorsky, Andronikos was determined to root out corruption: Under his rule, the sale of offices ceased; selection was based on merit, rather than favouritism; officials were paid an adequate salary so as to reduce the temptation of bribery. In the provinces, Andronikos''s reforms produced a speedy and marked improvement. The aristocrats were infuriated against him, and to make matters worse, Andronikos seems to have become increasingly unbalanced; executions and violence became increasingly common, and his reign turned into a reign of terror. Andronikos seemed almost to seek the extermination of the aristocracy as a whole. The struggle against the aristocracy turned into wholesale slaughter, while the Emperor resorted to ever more ruthless measures to shore up his regime.

Despite his military background, Andronikos failed to deal with Isaac Komnenos, Béla III of Hungary (r. 1172–1196) who reincorporated Croatian territories into Hungary, and Stephen Nemanja of Serbia (r. 1166–1196) who declared his independence from the Byzantine Empire. Yet, none of these troubles would compare to William II of Sicily''s (r. 1166–1189) invasion force of 300 ships and 80,000 men, arriving in 1185. Andronikos mobilised a small fleet of 100 ships to defend the capital, but other than that he was indifferent to the populace. He was finally overthrown when Isaac Angelos, surviving an imperial assassination attempt, seized power with the aid of the people and had Andronikos killed.

The reign of Isaac II, and moreso that of his brother Alexios III, saw the collapse of what remained of the centralised machinery of Byzantine government and defence. Although the Normans were driven out of Greece, in 1186 the Vlachs and Bulgars began a rebellion that led to the formation of the Second Bulgarian Empire. The internal policy of the Angeloi was characterised by the squandering of the public treasure and fiscal maladministration. Imperial authority was severely weakened, and the growing power vacuum at the center of the Empire encouraged fragmentation. There is evidence that some Komnenian heirs had set up a semi-independent state in Trebizond before 1204. According to Alexander Vasiliev, "the dynasty of the Angeloi, Greek in its origin, ... accelerated the ruin of the Empire, already weakened without and disunited within."

Fourth Crusade For more details on this topic, see Fourth Crusade.The Entry of the Crusaders into Constantinople, by Eugène Delacroix (1840).

In 1198, Pope Innocent III broached the subject of a new crusade through legates and encyclical letters. The stated intent of the crusade was to conquer Egypt, now the centre of Muslim power in the Levant. The crusader army that arrived at Venice in the summer of 1202 was somewhat smaller than had been anticipated, and there were not sufficient funds to pay the Venetians, whose fleet was hired by the crusaders to take them to Egypt. Venetian policy under the ageing and blind but still ambitious Doge Enrico Dandolo was potentially at variance with that of the Pope and the crusaders, because Venice was closely related commercially with Egypt. The crusaders accepted the suggestion that in lieu of payment they assist the Venetians in the capture of the (Christian) port of Zara in Dalmatia (vassal city of Venice, which had rebelled and placed itself under Hungary''s protection in 1186). The city fell in November 1202 after a brief siege. Innocent, who was informed of the plan but his veto disregarded, was reluctant to jeopardise the Crusade, and gave conditional absolution to the crusaders—not, however, to the Venetians.

After the death of Theobald III, Count of Champagne, the leadership of the Crusade passed to Boniface of Montferrat, a friend of the Hohenstaufen Philip of Swabia. Both Boniface and Philip had married into the Byzantine Imperial family. In fact, Philip''s brother-in-law, Alexios Angelos, son of the deposed and blinded Emperor Isaac II Angelos, had appeared in Europe seeking aid and had made contacts with the crusaders. Alexios offered to reunite the Byzantine church with Rome, pay the crusaders 200,000 silver marks, join the crusade and provide all the supplies they needed to get to Egypt. Innocent was aware of a plan to divert the Crusade to Constantinople and forbade any attack on the city, but the papal letter arrived after the fleets had left Zara.

Crusader sack of Constantinople (1204) Further information: Siege of Constantinople (1203) and Siege of Constantinople (1204)The partition of the empire following the Fourth Crusade, c. 1204.

The crusaders arrived at Constantinople in the summer of 1203 and quickly attacked, started a major fire that damaged large parts of the city, and briefly seized control. Alexios III fled from the capital, and Alexios Angelos was elevated to the throne as Alexios IV along with his blind father Isaac. However, Alexios IV and Isaac II were unable to keep their promises and were deposed by Alexios V. The crusaders again took the city on 13 April 1204, and Constantinople was subjected to pillage and massacre by the rank and file for three days. Many priceless icons, relics, and other objects later turned up in Western Europe, a large number in Venice. According to Choniates, a prostitute was even set up on the Patriarchal throne. When Innocent III heard of the conduct of his crusaders, he castigated them in no uncertain terms. But the situation was beyond his control, especially after his legate, on his own initiative, had absolved the crusaders from their vow to proceed to the Holy Land. When order had been restored, the crusaders and the Venetians proceeded to implement their agreement; Baldwin of Flanders was elected Emperor of a new Latin Empire, and the Venetian Thomas Morosini was chosen as Patriarch. The lands divided up among the leaders included most of the former Byzantine possessions, though resistance would continue through the Byzantine remnants of the Nicaea, Trebizond, and Epirus. Although Venice was more interested in commerce than conquering territory, it took key areas of Constantinople, and the Doge took the title of "Lord of a Quarter and Half a Quarter of the Roman Empire".

Fall Empire in exile For more details on this topic, see Latinokratia.

After the sack of Constantinople in 1204 by Latin crusaders, two Byzantine successor states were established: the Empire of Nicaea, and the Despotate of Epirus. A third one, the Empire of Trebizond was created a few weeks before the sack of Constantinople by Alexios I of Trebizond. Of these three successor states, Epirus and Nicaea stood the best chance of reclaiming Constantinople. The Nicaean Empire struggled to survive the next few decades, however, and by the mid-13th century it had lost much of southern Anatolia.

The weakening of the Sultanate of Rûm following the Mongol invasion in 1242–43 allowed many beyliks and ghazis to set up their own principalities in Anatolia, weakening the Byzantine hold on Asia Minor. In time, one of the Beys, Osman I, created an empire that would eventually conquer Constantinople. However, the Mongol invasion also gave Nicaea a temporary respite from Seljuk attacks, allowing it to concentrate on the Latin Empire to its north.

The Empire of Nicaea, founded by the Laskarid dynasty, managed to reclaim Constantinople from the Latins in 1261 and defeat Epirus. This led to a short-lived revival of Byzantine fortunes under Michael VIII Palaiologos, but the war-ravaged Empire was ill-equipped to deal with the enemies that now surrounded it. To maintain his campaigns against the Latins, Michael pulled troops from Asia Minor and levied crippling taxes on the peasantry, causing much resentment. Massive construction projects were completed in Constantinople to repair the damage of the Fourth Crusade, but none of these initiatives was of any comfort to the farmers in Asia Minor suffering raids from Muslim ghazis.

Rather than holding on to his possessions in Asia Minor, Michael chose to expand the Empire, gaining only short-term success. To avoid another sacking of the capital by the Latins, he forced the Church to submit to Rome, again a temporary solution for which the peasantry hated Michael and Constantinople. The efforts of Andronikos II and later his grandson Andronikos III marked Byzantium''s last genuine attempts in restoring the glory of the Empire. However, the use of mercenaries by Andronikos II would often backfire, with the Catalan Company ravaging the countryside and increasing resentment towards Constantinople.

Rise of the Ottomans and fall of Constantinople Main articles: Byzantine–Ottoman Wars and Fall of ConstantinopleThe siege of Constantinople in 1453, according to a 15th-century French miniature.

The situation became worse for Byzantium during the civil wars after Andronikos III died. A six-year long civil war devastated the empire, allowing the Serbian ruler Stefan IV Dushan (r. 1331–1346) to overrun most of the Empire''s remaining territory and establish a short-lived "Serbian Empire". In 1354, an earthquake at Gallipoli devastated the fort, allowing the Ottomans (who were hired as mercenaries during the civil war by John VI Kantakouzenos) to establish themselves in Europe. By the time the Byzantine civil wars had ended, the Ottomans had defeated the Serbians and subjugated them as vassals. Following the Battle of Kosovo, much of the Balkans became dominated by the Ottomans.

The Byzantine emperors appealed to the West for help, but the Pope would only consider sending aid in return for a reunion of the Eastern Orthodox Church with the See of Rome. Church unity was considered, and occasionally accomplished by imperial decree, but the Orthodox citizenry and clergy intensely resented the authority of Rome and the Latin Rite. Some Western troops arrived to bolster the Christian defence of Constantinople, but most Western rulers, distracted by their own affairs, did nothing as the Ottomans picked apart the remaining Byzantine territories.

The Eastern Mediterranean just before the fall of Constantinople

Constantinople by this stage was underpopulated and dilapidated. The population of the city had collapsed so severely that it was now little more than a cluster of villages separated by fields. On 2 April 1453, Sultan Mehmed''s army of some 80,000 men and large numbers of irregulars laid siege to the city. Despite a desperate last-ditch defence of the city by the massively outnumbered Christian forces (c. 7,000 men, 2,000 of whom were foreign), Constantinople finally fell to the Ottomans after a two-month siege on 29 May 1453. The last Byzantine Emperor, Constantine XI Palaiologos, was last seen casting off his imperial regalia and throwing himself into hand-to-hand combat after the walls of the city were taken.

Political aftermath

By the time of the fall of Constantinople, the only remaining territory of the Byzantine Empire was the Despotate of the Morea (Peloponnese), which was ruled by brothers of the last Emperor, Thomas Palaiologos and Demetrios Palaiologos. The Despotate continued on as an independent state by paying an annual tribute to the Ottomans. Incompetent rule, failure to pay the annual tribute and a revolt against the Ottomans finally led to Mehmed II''s invasion of Morea in May 1460. Demetrios asked the Ottomans to invade and drive Thomas out. Thomas fled. The Ottomans moved through the Morea and conquered virtually the entire Despotate by the summer. Demetrios thought the Morea would be restored to him to rule, but it was incorporated into the Ottoman fold.

A few holdouts remained for a time. The island of Monemvasia refused to surrender and it was first ruled for a short time by a Catalan corsair. When the population drove him out they obtained the consent of Thomas to place themselves under the Pope''s protection before the end of 1460. The Mani Peninsula, on the Morea''s south end, resisted under a loose coalition of the local clans and then that area came under Venice''s rule. The very last holdout was Salmeniko, in the Morea''s northwest. Graitzas Palaiologos was the military commander there, stationed at Salmeniko Castle. While the town eventually surrendered, Graitzas and his garrison and some town residents held out in the castle until July 1461, when they escaped and reached Venetian territory.

Flag of the late Empire under the Palaiologoi, sporting the tetragrammic cross symbol of the Palaiologos dynasty.

The Empire of Trebizond, which had split away from the Byzantine Empire just weeks before Constantinople was taken by the Crusaders in 1204, became the last remnant and last de facto successor state to the Byzantine Empire. Efforts by the Emperor David to recruit European powers for an anti-Ottoman crusade provoked war between the Ottomans and Trebizond in the summer of 1461. After a month long siege, David surrendered the city of Trebizond on 14 August 1461.

The nephew of the last Emperor, Constantine XI, Andreas Palaiologos claimed to have inherited the title of Byzantine Emperor. He lived in the Morea until its fall in 1460, then escaped to Rome where he lived under the protection of the Papal States for the remainder of his life. Since the office of emperor had never been technically hereditary, Andreas'' claim would have been without merit under Byzantine law. However, the Empire had vanished, and Western states generally followed the Roman church sanctioned principles of hereditary sovereignty. Seeking a life in the west, Andreas styled himself Imperator Constantinopolitanus ("Emperor of Constantinople"), and sold his succession rights to both Charles VIII of France and the Catholic Monarchs. However, no one ever invoked the title after Andreas''s death.

Mehmed II and his successors continued to consider themselves heirs to the Roman Empire until the demise of the Ottoman Empire in the early 20th century. They considered that they had simply shifted its religious basis as Constantine had done before, and they continued to refer to their conquered Eastern Roman inhabitants (Orthodox Christians) as Rûm. Meanwhile, the Danubian Principalities (whose rulers also considered themselves the heirs of the Eastern Roman Emperors) harboured Orthodox refugees, including some Byzantine nobles.

At his death, the role of the emperor as a patron of Eastern Orthodoxy was claimed by Ivan III, Grand duke of Muscovy. He had married Andreas'' sister, Sophia Paleologue, whose grandson, Ivan IV, would become the first Tsar of Russia (tsar, or czar, meaning caesar, is a term traditionally applied by Slavs to the Byzantine Emperors). Their successors supported the idea that Moscow was the proper heir to Rome and Constantinople. The idea of the Russian Empire as the successive Third Rome was kept alive until its demise with the Russian Revolution.

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The Byzantine economy was among the most advanced in Europe and the Mediterranean for many centuries. Europe, in particular, was unable to match Byzantine economic strength until late in the Middle Ages. Constantinople was a prime hub in a trading network that at various times extended across nearly all of Eurasia and North Africa, in particular being the primary western terminus of the famous Silk Road. Until the first half of the 6th century and in sharp contrast with the decaying West, Byzantine economy was flourishing and resilient.

The Plague of Justinian and the Arab conquests would represent a substantial reversal of fortunes contributing to a period of stagnation and decline. Isaurian reforms and, in particular, Constantine V''s repopulation, public works and tax measures, marked the beginning of a revival that continued until 1204, despite territorial contraction. From the 10th century until the end of the 12th, the Byzantine Empire projected an image of luxury and travellers were impressed by the wealth accumulated in the capital.

The Fourth Crusade resulted in the disruption of Byzantine manufacturing and the commercial dominance of the Western Europeans in the eastern Mediterranean, events that amounted to an economic catastrophe for the Empire. The Palaiologoi tried to revive the economy, but the late Byzantine state would not gain full control of either the foreign or domestic economic forces. Gradually, it also lost its influence on the modalities of trade and the price mechanisms, and its control over the outflow of precious metals and, according to some scholars, even over the minting of coins.

One of the economic foundations of Byzantium was trade, fostered by the maritime character of the Empire. Textiles must have been by far the most important item of export; silks were certainly imported into Egypt, and appeared also in Bulgaria, and the West. The state strictly controlled both the internal and the international trade, and retained the monopoly of issuing coinage, maintaining a durable and flexible monetary system adaptable to trade needs.

The government attempted to exercise formal control over interest rates, and set the parameters for the activity of the guilds and corporations, in which it had a special interest. The emperor and his officials intervened at times of crisis to ensure the provisioning of the capital, and to keep down the price of cereals. Finally, the government often collected part of the surplus through taxation, and put it back into circulation, through redistribution in the form of salaries to state officials, or in the form of investment in public works.

Science, medicine and law See also: Byzantine science, Byzantine medicine and Byzantine lawThe frontispiece of the Vienna Dioscurides, which shows a set of seven famous physicians

The writings of Classical antiquity never ceased to be cultivated in Byzantium. Therefore, Byzantine science was in every period closely connected with ancient philosophy, and metaphysics. Although at various times the Byzantines made magnificent achievements in the application of the sciences (notably in the construction of the Hagia Sophia), after the 6th century Byzantine scholars made few novel contributions to science in terms of developing new theories or extending the ideas of classical authors.

Scholarship particularly lagged during the dark years of plague and the Arab conquests, but then during the so-called Byzantine Renaissance at the end of the first millennium Byzantine scholars re-asserted themselves becoming experts in the scientific developments of the Arabs and Persians, particularly in astronomy and mathematics. The Byzantines are also credited with several technological advancements, particularly in architecture (e.g. the pendentive dome) and warfare technology (e.g. Greek fire).

In the final century of the Empire, Byzantine grammarians were those principally responsible for carrying, in person and in writing, ancient Greek grammatical and literary studies to early Renaissance Italy. During this period, astronomy and other mathematical sciences were taught in Trebizond; medicine attracted the interest of almost all scholars.

In the field of law, Justinian I''s reforms had a clear effect on the evolution of jurisprudence, and Leo III''s Ecloga influenced the formation of legal institutions in the Slavic world. In the 10th century, Leo VI the Wise achieved the complete codification of the whole of Byzantine law in Greek, which became the foundation of all subsequent Byzantine law, generating interest to the present day.

ReligionAs a symbol and expression of the universal prestige of the Patriarchate of Constantinople, Justinian built the Church of the Holy Wisdom of God, Hagia Sophia, which was completed in the short period of four and a half years (532–537)Main article: State church of the Roman Empire

The survival of the Empire in the East assured an active role of the Emperor in the affairs of the Church. The Byzantine state inherited from pagan times the administrative, and financial routine of administering religious affairs, and this routine was applied to the Christian Church. Following the pattern set by Eusebius of Caesarea, the Byzantines viewed the Emperor as a representative or messenger of Christ, responsible particularly for the propagation of Christianity among pagans, and for the "externals" of the religion, such as administration and finances. As Cyril Mango points out, the Byzantine political thinking can be summarised in the motto "One God, one empire, one religion".

The imperial role in the affairs of the Church never developed into a fixed, legally defined system. With the decline of Rome, and internal dissension in the other Eastern Patriarchates, the Church of Constantinople became, between the 6th and 11th centuries, the richest and most influential center of Christendom. Even when the Empire was reduced to only a shadow of its former self, the Church continued to exercise significant influence both inside and outside of the imperial frontiers. As George Ostrogorsky points out:

The Patriarchate of Constantinople remained the center of the Orthodox world, with subordinate metropolitan sees and archbishoprics in the territory of Asia Minor and the Balkans, now lost to Byzantium, as well as in Caucasus, Russia and Lithuania. The Church remained the most stable element in the Byzantine Empire.

The official state Christian doctrine was determined by the first seven ecumenical councils, and it was then the emperor''s duty to impose it to his subjects. An imperial decree of 388, which was later incorporated into the Codex Justinianus, orders the population of the Empire "to assume the name of Catholic Christians", and regards all those who will not abide by the law as "mad and foolish persons"; as followers of "heretical dogmas".

Despite imperial decrees and the stringent stance of the state church itself, which came to be known as the Eastern Orthodox Church or Eastern Christianity, the latter never represented all Christians in Byzantium. Mango believes that, in the early stages of the Empire, the "mad and foolish persons", those labelled "heretics" by the state church, were the majority of the population. Besides the pagans, who existed until the end of the 6th century, and the Jews, there were many followers – sometimes even emperors – of various Christian doctrines, such as Nestorianism, Monophysitism, Arianism, and Paulicianism, whose teachings were in some opposition to the main theological doctrine, as determined by the Ecumenical Councils.

Another division among Christians occurred, when Leo III ordered the destruction of icons throughout the Empire. This led to a significant religious crisis, which ended in mid-9th century with the restoration of icons. During the same period, a new wave of pagans emerged in the Balkans, originating mainly from Slavic people. These were gradually Christianised, and by Byzantium''s late stages, Eastern Orthodoxy represented most Christians and, in general, most people in what remained of the Empire.

Jews were a significant minority in the Byzantine state throughout its history, and, according to Roman law, they constituted a legally recognised religious group. In the early Byzantine period they were generally tolerated, but then periods of tensions and persecutions ensued. In any case, after the Arab conquests, the majority of Jews found themselves outside the Empire; those left inside the Byzantine borders apparently lived in relative peace from the 10th century onwards.

Georgian monasteries first appear in Constantinople and on Mount Olympos in northwestern Asia Minor in the second half of the ninth century, and from then on Georgians played an increasingly important role in the Empire.

Art and literatureMiniatures of the 6th-century Rabula Gospel display the more abstract and symbolic nature of Byzantine art.Main articles: Byzantine art and Byzantine literature See also: Byzantine music and Byzantine dress

Surviving Byzantine art is mostly religious and with exceptions at certain periods is highly conventionalised, following traditional models that translate carefully controlled church theology into artistic terms. Painting in fresco, illuminated manuscripts and on wood panel and, especially in earlier periods, mosaic were the main media, and figurative sculpture very rare except for small carved ivories. Manuscript painting preserved to the end some of the classical realist tradition that was missing in larger works. Byzantine art was highly prestigious and sought-after in Western Europe, where it maintained a continuous influence on medieval art until near the end of the period. This was especially so in Italy, where Byzantine styles persisted in modified form through the 12th century, and became formative influences on Italian Renaissance art. But few incoming influences affected Byzantine style. By means of the expansion of the Eastern Orthodox church, Byzantine forms and styles spread to all the Orthodox world and beyond. Influences from Byzantine architecture, particularly in religious buildings, can be found in diverse regions from Egypt and Arabia to Russia and Romania.

In Byzantine literature, four different cultural elements are recognised: the Greek, the Christian, the Roman, and the Oriental. Byzantine literature is often classified in five groups: historians and annalists, encyclopaedists (Patriarch Photios, Michael Psellus, and Michael Choniates are regarded as the greatest encyclopaedists of Byzantium) and essayists, and writers of secular poetry. The only genuine heroic epic of the Byzantines is the Digenis Acritas. The remaining two groups include the new literary species: ecclesiastical and theological literature, and popular poetry.

Of the approximately two to three thousand volumes of Byzantine literature that survive, only three hundred and thirty consist of secular poetry, history, science and pseudo-science. While the most flourishing period of the secular literature of Byzantium runs from the 9th to the 12th century, its religious literature (sermons, liturgical books and poetry, theology, devotional treatises, etc.) developed much earlier with Romanos the Melodist being its most prominent representative.

Government and bureaucracy See also: Byzantine aristocracy and bureaucracy

In the Byzantine state, the emperor became the sole and absolute ruler, and his power was regarded as having divine origin. The Senate ceased to have real political and legislative authority but remained as an honorary council with titular members. By the end of the 8th century, a civil administration focused on the court was formed as part of a large-scale consolidation of power in the capital (the rise to pre-eminence of the position of sakellarios is related to this change). The most important administrative reform, which probably started in the mid-7th century, was the creation of themes, where civil and military administration was exercised by one person, the strategos.

The themes, c. 650The themes, c. 950

Despite the occasionally derogatory use of the terms "Byzantine" and "Byzantinism", the Byzantine bureaucracy had a distinct ability for reconstituting itself in accordance with the Empire''s situation. The elaborate system of titulature and precedence, which gave the court prestige and influence, makes the imperial administration look like an ordered bureaucracy to modern observers. Officials were arranged in strict order around the emperor, and depended upon the imperial will for their ranks. There were also actual administrative jobs, but authority could be vested in individuals rather than offices.

In the 8th and 9th centuries, civil service constituted the clearest path to aristocratic status, but, starting in the 9th century, the civil aristocracy was rivalled by an aristocracy of nobility. According to some studies of Byzantine government, 11th-century politics were dominated by competition between the civil and the military aristocracy. During this period, Alexios I undertook important administrative reforms, including the creation of new courtly dignities and offices.

Diplomacy For more details on this topic, see Byzantine diplomacy.The embassy of John the Grammarian in 829, between the emperor Theophilos and the Abbasid caliph Al-Ma''mun

After the fall of Rome, the key challenge to the Empire was to maintain a set of relations between itself and its neighbours. When these nations set about forging formal political institutions, they often modelled themselves on Constantinople. Byzantine diplomacy soon managed to draw its neighbours into a network of international and inter-state relations. This network revolved around treaty making, and included the welcoming of the new ruler into the family of kings, and the assimilation of Byzantine social attitudes, values and institutions. Whereas classical writers are fond of making ethical and legal distinctions between peace and war, Byzantines regarded diplomacy as a form of war by other means. For example, a Bulgarian threat could be countered by providing money to the Kievan Rus''.

Diplomacy in the era was understood to have an intelligence-gathering function on top of its pure political function. The Bureau of Barbarians in Constantinople handled matters of protocol and record keeping for any issues related to the "barbarians", and thus had, perhaps, a basic intelligence function itself. John B. Bury believed that the office exercised supervision over all foreigners visiting Constantinople, and that they were under the supervision of the Logothetes tou dromou. While on the surface a protocol office – its main duty was to ensure foreign envoys were properly cared for and received sufficient state funds for their maintenance, and it kept all the official translators – it probably had a security function as well.

Byzantines availed themselves of a number of diplomatic practices. For example, embassies to the capital would often stay on for years. A member of other royal houses would routinely be requested to stay on in Constantinople, not only as a potential hostage, but also as a useful pawn in case political conditions where he came from changed. Another key practice was to overwhelm visitors by sumptuous displays. According to Dimitri Obolensky, the preservation of the ancient civilisation in Europe was due to the skill and resourcefulness of Byzantine diplomacy, which remains one of Byzantium''s lasting contributions to the history of Europe.

Language For more details on this topic, see Medieval Greek.Left: The Mudil Psalter, the oldest complete psalter in the Coptic language (Coptic Museum, Egypt, Coptic Cairo).

Apart from the Imperial court, administration and military, the primary language used in the eastern Roman provinces even before the decline of the Western Empire was Greek, having been spoken in the region for centuries before Latin. Following Rome''s conquest of the east its ''Pax Romana'', inclusionist political practices and development of public infrastructure, facilitated the further spreading and entrenchment of Greek language in the east. Indeed early on in the life of the Roman Empire, Greek had become the common language in the Christian Church, the language of scholarship and the arts, and, to a large degree, the lingua franca for trade between provinces and with other nations. The language itself for a time gained a dual nature with the primary spoken language, the constantly developing vernacular Koine (eventually evolving into demotic Greek), existing alongside an older literary language with Koine eventually evolving into the standard dialect.

Administrative usage of Latin persisted until the seventh century, when it was ended by Heraclius. Scholarly Latin would rapidly fall into disuse among the educated classes although the language would continue to be at least a ceremonial part of the Empire''s culture for some time. Additionally, Vulgar Latin remained a minority language in the Empire, and among the Thraco-Roman populations it gave birth to the Proto-Romanian language.

Likewise, on the coast of the Adriatic Sea, another neo-Latin vernacular developed, which would later give rise to the Dalmatian language. In the Western Mediterranean provinces temporarily acquired under the reign of emperor Justinian I, Latin (eventually evolving into the various western Romance languages) continued to be used both as a spoken language and the language of scholarship.

Many other languages existed in the multi-ethnic Empire, and some of these were given limited official status in their provinces at various times. Notably, by the beginning of the Middle Ages, Syriac and Aramaic had become more widely used by the educated classes in the far eastern provinces. Similarly Coptic, Armenian, and Georgian became significant among the educated in their provinces, and later foreign contacts made the Slavonic, Vlach, and Arabic languages important in the Empire and its sphere of influence.

Aside from these, since Constantinople was a prime trading center in the Mediterranean region and beyond, virtually every known language of the Middle Ages was spoken in the Empire at some time, even Chinese. As the Empire entered its final decline, the Empire''s citizens became more culturally homogeneous and the Greek language became integral to their identity and religion.

Legacy See also: Third Rome and Greek scholars in the RenaissanceKing David in robes of a Byzantine emperor; miniature from the Paris Psalter

Byzantium has been often identified with absolutism, orthodox spirituality, orientalism and exoticism, while the terms "Byzantine" and "Byzantinism" have been used as bywords for decadence, complex bureaucracy, and repression. In the countries of Central and Southeast Europe that exited the Eastern Bloc in the late 1980s and early 1990s, the assessment of Byzantine civilisation and its legacy was strongly negative due to their connection with an alleged "Eastern authoritarianism and autocracy." Both Eastern and Western European authors have often perceived Byzantium as a body of religious, political, and philosophical ideas contrary to those of the West. Even in 19th-century Greece, the focus was mainly on the classical past, while Byzantine tradition had been associated with negative connotations.

This traditional approach towards Byzantium has been partially or wholly disputed and revised by modern studies, which focus on the positive aspects of Byzantine culture and legacy. Averil Cameron regards as undeniable the Byzantine contribution to the formation of the medieval Europe, and both Cameron and Obolensky recognise the major role of Byzantium in shaping Orthodoxy, which in turn occupies a central position in the history and societies of Greece, Bulgaria, Russia, Serbia and other countries. The Byzantines also preserved and copied classical manuscripts, and they are thus regarded as transmitters of the classical knowledge, as important contributors to the modern European civilisation, and as precursors of both the Renaissance humanism and the Slav Orthodox culture.

As the only stable long-term state in Europe during the Middle Ages, Byzantium isolated Western Europe from newly emerging forces to the East. Constantly under attack, it distanced Western Europe from Persians, Arabs, Seljuk Turks, and for a time, the Ottomans. From a different perspective, since the 7th century, the evolution and constant reshaping of the Byzantine state were directly related to the respective progress of Islam.

Following the conquest of Constantinople by the Ottoman Turks in 1453, Sultan Mehmed II took the title "Kaysar-i Rûm" (the Ottoman Turkish equivalent of Caesar of Rome), since he was determined to make the Ottoman Empire the heir of the Eastern Roman Empire. According to Cameron, regarding themselves as "heirs" of Byzantium, the Ottomans preserved important aspects of its tradition, which in turn facilitated an "Orthodox revival" during the post-communist period of the Eastern European states.